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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Puyou Lu <puyou.lu@gmail.com>,
        Bartosz Golaszewski <brgl@bgdev.pl>
Subject: [PATCH 5.15 041/135] gpio: pca953x: fix irq_stat not updated when irq is disabled (irq_mask not set)
Date:   Tue, 10 May 2022 15:07:03 +0200
Message-Id: <20220510130741.579131175@linuxfoundation.org>
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From: Puyou Lu <puyou.lu@gmail.com>

commit dba785798526a3282cc4d0f0ea751883715dbbb4 upstream.

When one port's input state get inverted (eg. from low to hight) after
pca953x_irq_setup but before setting irq_mask (by some other driver such as
"gpio-keys"), the next inversion of this port (eg. from hight to low) will not
be triggered any more (because irq_stat is not updated at the first time). Issue
should be fixed after this commit.

Fixes: 89ea8bbe9c3e ("gpio: pca953x.c: add interrupt handling capability")
Signed-off-by: Puyou Lu <puyou.lu@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpio/gpio-pca953x.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -762,11 +762,11 @@ static bool pca953x_irq_pending(struct p
 	bitmap_xor(cur_stat, new_stat, old_stat, gc->ngpio);
 	bitmap_and(trigger, cur_stat, chip->irq_mask, gc->ngpio);
 
+	bitmap_copy(chip->irq_stat, new_stat, gc->ngpio);
+
 	if (bitmap_empty(trigger, gc->ngpio))
 		return false;
 
-	bitmap_copy(chip->irq_stat, new_stat, gc->ngpio);
-
 	bitmap_and(cur_stat, chip->irq_trig_fall, old_stat, gc->ngpio);
 	bitmap_and(old_stat, chip->irq_trig_raise, new_stat, gc->ngpio);
 	bitmap_or(new_stat, old_stat, cur_stat, gc->ngpio);